Pile Heave and Redriving

Upward pile movement or “pile heave” commonly occurs whenever large numbers of closely spaced piles are driven. Pile heave is generally attributed to displacement of the foundation soils during subsequent driving of adjacent piles. The majority of engineers appear to be of the opinion that all heaved piles must be redriven. Very few documented case histories dealing with this problem are available in the engineering literature. This paper presents detailed field data with analyses pertaining to pile-heave problems that developed during construction of end-bearing pile foundations for a large industrial plant. Two individual areas within the plantsite are selected for detailed study. Pile heave occurred at both areas. However, whereas in one area the heaving constituted a serious foundation problem necessitating the redriving of all heaved piles, in the other area it presented no problem and redriving was not necessary. The successful performance of the completed pile foundations at both areas is confirmed by settlement observation data maintained on the buildings since construction. The paper shows that each pile-heave problem must be evaluated on its own merits. In order to carry out such an evaluation, adequate data concerning such items as subsoil profile, magnitude of pile heave, magnitude of ground heave, pile penetration diagrams, and pile loading tests must be gathered and studied. From such a study, the mechanics of the specific pile heaving process may be determined and consequently its probable effects on the performance of the completed structures evaluated.